As I wrote earlier, to bypass iCloud on your iPad Wi-Fi Only you need to change the serial number. The easiest way to do this using a special device to change the serial number. But this device is expensive.

If you are a highly skilled electrician, you can replace the NAND chip on your iCloud locked iPad Wi-Fi Only. New NAND chip => new serial number => new iPad or iPod with bypassed iCloud.

As donor you can use chips from other iPhone or iPad Cellular without iCloud or buy kit of 3 iCloud free chips in Asian stores. Stores is better way. It costs about $10. You should use only compatible devices.

Using a soldering station to heat the chip and remove it from the board. Then put the new chip at the place of the old. Warm chip to melt the solder.

Destroy the old chip, solder and glue residues. Then put the new chip at the place of the old. Warm chip to melt the solder.

The first method is cheaper and does not require additional equipment. But you can easily kill your iPad Cellular or iPhone board. You can overheat it. Overheating will kill some of the components on the board. For example, a processor. Or twisted logic board. In result you will need to buy new device.

First way and full bypass:

If you want to do it in large quantities then buy special equipment for the second method. Here some videos how to make second method.

After changing chips in your iCloud locked iPad Cellular or iPhone restore this device as usual in iTunes. Now you bypassed iCloud.